1. Technical Field
The present invention relates to a passenger seat air bag which is installed in an instrument panel in front of a passenger seat of a vehicle. Particularly, it relates to a passenger seat air bag in which the bottom side of an air bag body is rolled, next the top side of the air bag body is rolled, and then the left side and the right side of the air bag body are folded. In addition, the invention relates to a passenger seat air bag apparatus provided with the passenger seat air bag, and a vehicle provided with the passenger seat air bag apparatus.
2. Related Art
A passenger seat air bag has been disclosed in Patent Literature 1. In the passenger seat air bag, the bottom side of an air bag body is rolled to form a bottom side folded piece. Next, the top side of the air bag body is rolled and put on the bottom side folded piece so as to form a laminated piece. Then, the left side and the right side of the laminated piece are rolled to form a left side folded piece and a right side folded piece respectively so that a space is formed between the left side folded piece and the right side folded piece.
The top side represents a part composing the upper side of the air bag when the air bag is completely inflated, and the bottom side represents a part composing the lower side of the air bag when the air bag is completely inflated. On the other hand, the left and right represent the left and right of a passenger on a passenger seat.
In this Patent Literature 1, as shown in FIG. 1, vent holes are provided in the middle in an up-down direction and on the leftmost side and the rightmost side. Thus, the vent holes are involved in the left side folded piece and the right side folded piece.
A passenger seat air bag which is configured so that a diffuser is placed in an air bag body so as to regulate the flow of gas from an inflator has been disclosed in each of Patent Literatures 2 and 3. In Patent Literature 2, the direction of the flow of gas from the inflator is regulated in the left-right direction by the diffuser. In Patent Literature 3, gas outlets provided in the diffuser (referred to as inner bag in Patent Literature 3) are displaced in the up-down direction or the left-right direction from the direction right behind the vehicle so as to inflate the air bag softly for a passenger on the passenger seat or a child in front thereof.